[Risks factors for death among COVID-19 patients combined with hypertension, coronary heart disease or diabetes]

OBJECTIVE

The pathogenesis of myocardial injury upon corona virus disease 2019 (COVID-19) infection remain unknown,evidence of impact on outcome is insufficient, therefore, we aim to investigate the risk factors for death among COVID-19 patients combined with hypertension, coronary heart disease or diabetes in this study.

METHODS

This was a single-centered, retrospective, observational study. Patients of Sino-French Eco-City section of Tongji Hospital, Wuhan, China attended by Peking University Supporting Medical Team and admitted from Jan. 29, 2020 to Mar. 20, 2020 were included. The positive nucleic acid of COVID-19 virus and combination with hypertension, coronary heart disease or diabetes were in the standard. We collected the clinical data and laboratory examination results of the eligible patients to evaluate the related factors of death.

RESULTS

In the study, 94 COVID-19 patients enrolled were divided into the group of death (13 cases) and the group of survivors (81 cases), the average age was 66.7 years. Compared with the survival group, the death group had faster basal heart rate(103.2 beats/min vs. 88.4 beats /min, P=0.004), shortness of breath(29.0 beats /min vs. 20.0 beats /min, P<0.001), higher neutrophil count(9.2×10⁹/L vs. 3.8×10⁹/L, P<0.001), lower lymphocyte count(0.5×10⁹/L vs. 1.1×10⁹/L, P<0.001), creatine kinase MB(CK-MB, 3.2 μg/L vs. 0.8 μg/L, P<0.001), high sensitivity cardiac troponin Ⅰ(hs-cTnⅠ, 217.2 ng/L vs. 4.9 ng/L, P<0.001), N-terminal pro brain natriuretic peptide(NT-proBNP; 945.0 μg/L vs. 154.0 μg/L, P<0.001), inflammatory factor ferritin(770.2 μg/L vs. 622.8 μg/L , P=0.050), interleukin-2 recepter(IL-2R, 1 586.0 U/mL vs. 694.0 U/mL, P<0.001), interleukin-6(IL-6, 82.3 ng/L vs. 13.0 ng/L, P<0.001), interleukin-10(IL-10, 9.8 ng/L vs. 5.0 ng/L, P<0.001)were higher than those in the survival group. Univariate logistic regression analysis showed that the risk factors for death were old age, low non oxygen saturation, low lymphocyte count, myocardial injury, abnormal increase of IL 2R, IL-6, and IL-10. Multivariate regression showed that old age (OR=1.11, 95%CI=1.03-1.19, P=0.026), low non oxygen saturation(OR=0.85, 95%CI=0.72-0.99, P=0.041), and abnormal increase of IL-10(＞9.1 ng/L, OR=101.93, 95%CI=4.74-2190.71, P=0.003)were independent risk factors for COVID-19 patients combined with hypertension, coronary heart disease or diabetes.

CONCLUSION

In COVID-19 patients combined with hypertension, coronary heart disease or diabetes, the risk factors for death were old age, low non oxygen saturation, low lymphocyte count, myocardial injury, and abnormal increase of IL-2R, IL-6, and IL-10. Old age, low non oxygen saturation and abnormal increase of IL-10 were independent risk factors.

[Clinical experience of minimal invasive coronary surgery-coronary artery bypass grafting: a series of 244 cases]

Objective: To examine the safety and efficacy of minimally invasive coronary surgery-coronary artery bypass grafting (MICS-CABG). Methods: From the first case in November 2015 to November 2019, a total of 244 cases of MICS-CABG were performed in Department of Cardiovascular Surgery, Peking University Third Hospital. There were 197 males and 47 females, aging (62.3±8.7)years (range: 36 to 88 years). The operations were performed via the 5(th) intercostal space of left thoracic lateral incision (length: 4 to 5 cm extended for 8 to 10 cm), and were performed under off-pump, with the help of the chest wall suspension device and cardiac fixator. The proximal anastomosis on ascending aorta and the distal anastomosis of left anterior descending branch, circumflex branch and right coronary system were completed according to procedure. In all 244 cases, the proportion of 2 grafts was 53.7% (131 cases), 3 grafts was 36.1% (88 cases), 4 grafts was 9.8% (24 cases) and 5 grafts was 0.4% (1 case). The average of grafts was 2.6±0.7 (range: 2 to 5). The proportion of hybrid was 14.3% (35 cases), sequential bypass procedure was 43.0% (105 cases) and multiple artery grafts was 25.4% (62 cases). The perioperative complications of the patients were collected, the patency rate of the grafts was evaluated by coronary angiography or CT within 7 days after the operation, and main adverse cardiovascular and cerebrovascular events (MACCE) were followed up. The survival curve was drawn by Kaplan-Meier method, and the 1-year MACCE rate was calculated by survival analysis. Results: All cases had no transition to thoracotomy and cardiopulmonary bypass procedure, and no cases needed intra aortic balloon pumping and extracorporeal membrane oxygenation during the operation.There were 2 cases of poor incision healing, and reoperation was performed in 10 cases (6 cases of postoperative bleeding, 2 cases of incision debridement, and 2 cases of grafts problems). The rate of MACCE in 30 days was 2.6% (10 cases), which contained 3 cases of death (2 cases of grafts occlusion, 1 case of serious hemorrhage after thoracic puncture drainage), 3 cases of stroke and 5 cases of non-fatal myocardial infarction. By the re-examination of angiography in 7 days after operation, the overall patency of the grafts was 96.1%, and the patency of the left anterior descending was 98.6%. Kaplan-Meier survival analysis was conducted for 235 patients (96.3%) with 1 to 36 months follow-up results, and the 1-year MACCE rate was 5.6% (95%CI: 4.2% to 7.0%) . There was no significant difference among the incidences of MACCE at each stage of learning curve. Surgeon could reduce the operation time and complete more anastomosis with the accumulation of experience after the early 30 cases. Conclusions: MICS-CABG can safely achieve completed revascularization, which has good operative effects in short and medium-long term. There is no significant risk in the early cases of learning curve.

[Early clinical outcomes of minimally invasive coronary surgery-total arterial coronary revascularization]

Objective: To summarize the early experience and clinical value of minimally invasive coronary surgery-total arterial coronary revascularization (MICS-TACR) through the left anterior small incision. Methods: Between May 2015 and June 2018, a total of 31 consecutive cases [21 males and 10 females, aged (63.2±9.3) years] in Peking University Third Hospital who were performed MICS-TACR with bilateral internal mammary artery and radial artery were enrolled. Meanwhile, 1 489 cases of conventional median sternal incision off-pump coronary artery bypass grafting (OPCABG) were matched as control group. According to exclusion criteria and matching score, 90 cases [55 males and 35 females, aged (63.8±9.5) years] were selected as the control group, and the perioperative data of the two groups were compared. All patients in MICS-TACR group underwent postoperative angiography and the graft patency was evaluated. Results: There were no statistically significant differences in baseline data between the two groups. The perioperative blood transfusion of MICS-TACR group was less than control group [0(0,0) U vs 0(0,4) U, P=0.003]. There were no statistically significant differences in operative mortality, intraoperative and postoperative intra-aortic balloon pump (IABP) and extracorporeal membrane oxygenation (ECMO) use, re-operation rate, perioperative major adverse cardiac and cerebrovascular events (MACCE), new-onset renal failure, atrial fibrillation, and multiple organ failure between the two groups. Postoperative angiography showed that there was no significant difference in the patency rate between the MICS-TACR group and control group(all P>0.05). Conclusion: Total arterial coronary revascularization can be successfully accomplished under the left anterior small incision, and the early clinical outcome is satisfied.

[Mid-term multi-center outcomes of bilateral radial artery as conduits in coronary artery bypass grafting]

Objective: To evaluate the mid-term outcomes of bilateral radial artery (BRA) grafts in coronary artery bypass grafting (CABG). Methods: All perioperative medical records and follow-up results of CABG with BRA grafts in multi-centers of China were analyzed retrospectively. Results: A total of 211 patients (170 males and 41 females) underwent CABG grafting with BRA conduits between August 2013 and September 2018, with a mean age of (56.5±9.7) years old (rang 41 to 73 years). There were 161 cases of triple-vessel disease and 50 cases of two-vessel disease. Ninety patients had diabetes mellitus (DM), 35 patients with peripheral vascular disease, 4 patients with chronic obstructive pulmonary disease and 11 with heart valve disease. Two patients underwent off-pump CABG and 209 patients accepted on-pump CABG with commitment valve surgery. There were 210 cases of total arterial revascularization and 161 cases using left thoracic artery conduits, with a graft number of 2-4 (2.7±0.9). No operation-related death occurred, atrial fibrillation happened in 12 patients, hemothorax in 7 cases, and forearm hematoma in one case, hypoxemia in 13 cases and pneumonia in one case. The duration of mechanical ventilation was (8.3±4.7) hours and the mean hospital length of stay was (7.1±2.9) days. Follow-up was completed in 191 patients (90.52%) with a duration of 3-59 (35.5±9.3) months. The mean left ventricular ejection fraction at 3 months after operation was significantly improved, compared to that of the pre-operation (61.0%±7.2% vs 47.1%±5.3%, P=0.017). All patients survived, except that one died from brain injury. No major cardiac events occurred, with a cumulative survival rate of 100% at 1 year and 99.53% at 3 year after operation, respectively. It was showed in coronary CT angiography (CTA) examination that all grafts in 132 patients were patent at the mean follow-up duration of (21.5±6.4) months. Conclusions: BRA grafts as arterial conduit in CABG are proved to be safe, easy for total arterial revascularization and have good mid-term clinical results.

Physicochemical evaluation and in vitro hemocompatibility study on nanoporous hydroxyapatite

Hydroxyapatite is an ideal biomaterial for bone tissue engineering due to its biocompatibility and hemocompatibility which have been widely studied by many researchers. The incorporation of nanoporosity into hydroxyapatite could transform the biomaterial into an effective adsorbent for uremic toxins removal especially in artificial kidney system. However, the effect of nanoporosity incorporation on the hemocompatibility of hydroxyapatite has yet to be answered. In this study, nanoporous hydroxyapatite was synthesized using hydrothermal technique and its hemocompatibility was determined. Non-ionic surfactants were used as soft templates to create porosity in the hydroxyapatite. The presence of pure hydroxyapatite phase in the synthesized samples is validated by X-ray diffraction analysis and Fourier transform infrared spectroscopy. The TEM images show that the hydroxyapatite formed rod-like particles with the length of 21-90 nm and diameter of 11-70 nm. The hydroxyapatite samples exhibit BET surface area of 33-45 m² g^-1 and pore volume of 0.35-0.44 cm³ g^-1. The hemocompatibility of the hydroxyapatite was determined via hemolysis test, platelet adhesion, platelet activation and blood clotting time measurement. The nanoporous hydroxyapatite shows less than 5% hemolysis, suggesting that the sample is highly hemocompatible. There is no activation and morphological change observed on the platelets adhered onto the hydroxyapatite. The blood clotting time demonstrates that the blood incubated with the hydroxyapatite did not coagulate. This study summarizes that the synthesized nanoporous hydroxyapatite is a highly hemocompatible biomaterial and could potentially be utilized in biomedical applications.

[Comparison of outcomes of two minimally invasive approaches for multi-vessel coronary revascularization]

OBJECTIVE

To compare the safety and effectiveness of two minimally invasive approaches for multi-vessel coronary revascularization.

METHODS

From August 2014 to February 2017, 70 consecutive patients who underwent minimally invasive coronary artery bypass grafting in Peking University Third Hospital were randomly divided into two groups. In one group, 40 patients underwent staged-hybrid coronary revascularization (staged-HCR) treatment; in the other group, 30 patients underwent minimally invasive total arterial revascularization with bilateral internal thoracic artery (BITA). In staged -HCR group, the patients underwent minimally invasive direct coronary artery bypass grafting (MIDCAB) and percutaneous coronary intervention (PCI) procedure for treatment of multi-vessel disease. In BITA group, the patients underwent total arterial coronary artery bypass grafting with composite "Y" BITA graft. Preoperative and postoperative data of the two groups, including postoperative blood usage, mechanical ventilation time, domiciling duration in intensive care unit (ICU), major adverse cerebral and cardiovascular event (MACCE), and postoperative coronary angiography results were compared, in order to evaluate the safety and effectiveness of these surgical approaches.

RESULTS

The preoperative characteristics of 70 patients in the two groups showed no significant difference. All the patients underwent successfully, elective minimally invasive multi-vessel coronary artery bypass grafting as scheduled preoperatively. Postoperative result showed the patients in staged-HCR group took advantages in less postoperative mechanical ventilation time [Staged-HCR group (11.2±8.7) h vs. BITA group (18.3±9.1) h, P=0.013], shorter domiciling duration in ICU [Staged-HCR group (26.29±4.05) h vs. BITA group (44.74±28.75) h, P=0.022], and less total drainage [Staged-HCR group (695.57±250.46) mL vs. BITA group (1 103.26±547.44) mL, P=0.03] than the patients in the group of minimally invasive total arterial revascularization with BITA. Postoperative in hospital coronary angiography showed satisfactory graft patency rates in both groups [97.5% in Staged-HCR group vs. 97.8% in BITA group]. No MACCE occurred in both groups during hospitalization.

CONCLUSION

Staged-HCR is a feasible method for the treatment of multi-vessel revascularization involving right coronary artery. Minimally coronary revascularization with BITA is associated with superior long-term graft patency and it's recommended for patients who could not tolerate dual-antiplatelet therapy. This study shows that both minimally invasive surgical approaches are safe and effective for treatment of patients with multi-vessel coronary artery disease.

[Acetylcholine and A23187 stimulate epinephrine secretion of isolated rat adrenal medulla cells in vitro]

Acetylcholine and A23187, two acetylcholinergic agonists, were used to induce the stimulus-secretion coupling of the isolated rat adrenal medulla cells. Morphometry of numerical density and electron probe X-ray quantitative microanalysis were adopted to measure the alterations in the number and calcium content of chromaffin granules in adrenal medulla cells during the agonist treatment. Secretion of epinephrine was detected by the high performance liquid chromatography (HPLC). It was found that the Ca content of the isolated rat adrenal medulla chromaffin granules dropped significantly after a 10-min incubation with the agonists, whereas the number of chromaffin granule decreased slowly during the agonist treatment and the epinephrine concentration raised significantly after a 20-min incubation with the agonists. The decrease of granule Ca content occurred earlier than the increase of epinephrine concentration, suggesting that the calcium released from chromaffin granule may in part account for the induced cell secretion.

[The relationship between the chromaffin granule number and the granule calcium content in the adrenal medulla of restrained rats]

Morphometry of numerical density and electron probe X-ray quantitative microanalysis were used to measure the alterations in the number and calcium content of chromaffin granules in adrenal medulla cells during emergency reaction of restrained rats. It was found that both the alterations showed monotonic decrease during the period of restraint, but the rate of decrease of the calcium content was significantly faster than that of the granules. These data are consistent with the hypothesis that calcium release from the granules may increase the cytoplasmic calcium concentration, which again triggers off the granule exocytosis.

[Atrial specific granules are an intracellular calcium store]

In order to elucidate whether the secretion of atrial natriuretic peptide (ANP) is correlated to the release of calcium (Ca) from the atrial specific granules (ASG), it is necessary to explore whether the ASG contain highly concentrated Ca and how the high Ca is maintained in the ASG. The present study was designed to determine Ca in the ASG with the quantitative electron microscope X-ray microanalysis and Ca(2+)-ATPase with electron microscopic (EM) cytochemical technique. The ultrathin cryosections of rapid frozen fresh rat auricles were used for measuring Ca concentration with a JEM-1200EX electron microscope equipped with a Link AN 10,000 energy dispersive X-ray spectroscope. The measurement showed that the Ca concentration in the ASG was quite high, being 81 +/- 15 mmol/kg (n = 10), comparable with that found in the sarcoplasmic reticulum. With the Ca(2+)-ATPase EM cytochemical technique, the reaction products proved to be deposited on the membrane of the ASG. It was postulated that the Ca(2+)-ATPase on the membrane of ASG pumped Ca2+ out of the cytosol into the ASG and thus maintained a high Ca concentration inside the ASG. Therefore, the ASG might be considered to be a Ca store in atrial cardiocytes.

X-ray microanalysis of calcium in ischemic skeletal muscle cells

Tissue sections of both transiently and persistently ischemic musculus latissimus dorsi of rabbits show degenerated and necrotic cells in varying degrees. Degenerated mitochondria appearing in the cells contain moderate electron-dense fluffy intramatrical deposits. However, only in the transient ischemia sample can other two kinds of electron-dense granules be seen between myofibrils. According to their ultrastructure, size and distribution, the larger granules are considered the degenerated mitochondria, and the smaller ones the degenerated sarcoplasmic reticulum. X-ray microanalysis proves that these two kinds of granules contain high concentration of calcium, while the fluffy deposits contain little calcium. The findings suggest that the calcium deposits in the degenerated and necrotic cell seen under light microscope occur in mitochondria and sarcoplasmic reticulum of the transiently ischemic muscle cell. The conditions of calcium accumulation in ischemic muscle cells are discussed.

Experimental study of regeneration of motor end plate

Twenty-five Wistar rats and five dogs were used in this study. The common peroneal nerve connected with a segment of nerve graft was divided into fascicles or subfascicles and then inserted into the superficial muscular fibers of the lateral head of the gastrocnemius. The motor nerve supplying this muscle was deliberately cut away during the operation. Electrograms muscular strength, optic and electron-microscopic, and histochemical examinations were studied 2 to 12 months postoperatively. New motor end plates and good muscular activity of the neurotized lateral head of the denervated gastrocnemius were demonstrated. This experimental result is useful for clinical applications of the method.